Regarding the concern about kicking (should you somehow end up not getting the first row of economy), I read some good advice on this site years ago (may have been from Eclipsepearl?). The person suggested removing the shoes of your little kicker. Kicking the seat in front of you in socks, is not nearly as fun as kicking it with shoes. Anyway, it worked for me when my kids were toddlers. I'd just keep their shoes on the floor and pop them back on for lavatory visits etc.

pintsizepilot - survival skills for travel with babies, toddlers and kids